Nowadays, the relevance of image sensors of camera devices is increasing as mobile devices, digital cameras, and other electronic devices become increasingly popular. An image sensor may sense light by using a photo diode and may output a digital image signal by using an analog to digital converter (ADC). An image sensor may comprise a plurality of pixels for the purpose of sensing light.
Image sensors that operate at higher speeds may be desirable to obtain a high-quality image. Accordingly, a way to provide a plurality of ADCs for simultaneously processing signals transferred from a plurality of pixels has been proposed. Because the a plurality of ADCs may be able to process signals simultaneously, the image sensor may be able to process a digital image signal at a high speed. As a result, a user may obtain high-quality image information.
However, in the case of using the plurality of ADCs together, a noise may occur due to a characteristic difference of the ADCs. Various ways to process a digital image signal are being proposed to reduce a noise.